What side effects can occur with intermittent fasting?

In general, intermittent fasting has very few side effects (Varady et al., 2022). Headaches sometimes occur when intermittent fasting is first started (Vardy et al., 2022). They are believed to be due to dehydration and increased water intake tends to resolve the headaches (Varady et al., 2022). What does NOT happen Intermittent fasting is NOT associated…